Last year, a young woman went online to get advice after she said a man she was casually seeing did something that made her feel "violated." They had gone back to his place one night and had consensual sex. She insisted on using a condom and saw him put it on, she said, only to later discover it had been removed.

“He admitted he took it off,” she wrote on Reddit, asking other users if she had overreacted by “freaking out.”

“I felt really violated," she said. "I told him it was unacceptable.”

The young woman is not alone. Similar stories and reactions are scattered across internet forums, with people describing their own experiences with men removing a condom during sex without their consent or knowledge.

Their narratives highlight a kind of gender-based assault that is common, but hardly discussed outside of internet groups: purposefully removing condoms during sex without consent, or “stealthing.” A new article in the Columbia Journal of Gender and Law delves into the act and how online groups are perpetuating and encouraging it, and argues that it violates a host of civil and criminal laws.

Alexandra Brodsky, a legal fellow at the National Women's Law Center and the study’s author, contends that stealthing transforms consensual sex into nonconsensual and is a “grave violation of dignity and autonomy.”

Brodsky interviewed a number of victims for the article, mostly women, who said their partner deliberately removed their condom without telling them, or lied about doing so.

One victim, identified as Rebecca, told Brodsky her boyfriend stealthed her when she was a freshman in college. The doctoral student started working at a rape crisis hotline and found many other women, most of them undergraduate students, shared a similar experience.

One in seven women have experienced a partner interfering with their contraception, according to the National Crime Victimization Survey. “Their stories often start the same way,” Rebecca told Brodsky. “’I’m not sure if this is rape, but...’”

One woman recalled why she felt betrayed: "Obviously the part that really freaked me out... was that it was such a blatant violation of what we'd agreed to. I set a boundary. I was very explicit."

Sara, another woman interviewed by Brodsky, said her experience felt similar to an assault and called it "rape-adjacent."

“They sensed something bad or wrong had happened to them and felt like a violation, but they didn’t have the vocabulary to describe or process it,” Brodsky told BuzzFeed News.

While each account was unique, Brodsky found they all shared similar themes: The overwhelming fear of getting pregnant, catching STIs, HIV, and AIDS, as well as feelings of betrayal, confusion, and shame, similar to those who’ve experienced other forms of sexual violence.

“Survivors [of stealthing] describe nonconsensual condom removal as a threat to their bodily agency and as a dignitary harm. ‘You have no right to make your own sexual decisions,’ they are told. ‘You are not worthy of my consideration,’” she writes.

Stealthing, Brodsky discovered, is a form of “male sexual supremacy” that’s garnered a loyal and broadening fanbase online, where some defend the act as a male right to “spread his seed,” and share tips and success stories and praise one another’s methods.

On the website Experience Project, for instance, a man with the username onesickmind penned "a comprehensive guide" to stealth sex, bragging that he has done this “over and over with so many girls i can't even begin to count them.”

Gay men are also often victims. Mark Bentson, who runs a fringe blog, notes that stealthing is controversial but calls it a "reality" and teaches his readers how to trick their partners into believing they are having "safer sex."

While stealthing is not legally defined as rape in the US, Brodsky argues there is a strong enough connection between the practice and sexual assault and victims should be protected by the law. Earlier this year, a Swiss court convicted a man of rape for taking off his condom.

"The law is often skeptical of survivors, especially if they have had a sexual history or past with someone," she said, explaining it is much harder for a person to argue they were assaulted by a partner who removed his condom after previously consenting to sex.

Leslie Tenzer, a professor at Pace Law School who specializes in torts, agreed, saying the law often "fail these victims," as they have to prove a level of physical harm. Under Brodsky's proposal, plaintiffs would be able to make a case "without the obstacle of proving the level of physical harm courts typically demand."

However, Tenzer contends it would be tough to pass a law with the changes in state legislatures, "many of which, in today's political climate, seem to be on the opposing side."

"Our society is used to excusing men and perpetuating the belief that men have access to women's bodies when they want," Brodsky said. "The law should support the belief that people have the right to their own bodies."

Brianna Sacks is a reporter for BuzzFeed News and is based in Los Angeles.